unless you are handed down watercooling parts where the only thing that you'd need to buy under the $40 mark would be distilled water(and maybe a silver kill coil) which is very cheap! Other than taht - going for a CLC even on discount is a no-go route IMO. H50's ...maybe, but considering all the leaks sprung forth from the other H's - I'd say no.
keeping my post more towards OP's question:
the HR02 checks out fine considering the case dimensions you have
CPU coolers up to 170mm tall (when no fan is installed in the side panel)
courtesy of Fractal